A bi-fuel delivery system, as used herein, is understood to be any engine system that is capable of operating on two different types of fuel. Conversion from a mono-fuel system, such as a diesel fuel combustion engine commonly found in heavy-duty trucks and buses sold by large-scale manufacturers of such vehicles, to a bi-fuel system is advantageous because the alternative fuels used, such as bio-diesel, vegetable oil and renewable diesel, are more environmentally friendly and sustainable and typically result in the reduction of total operational costs and lower vehicle emissions. There are, however, several challenges to converting a mono-fuel system into a bi-fuel system.
One problem with current bi-fuel systems is that when one of the fuel supplies is selected, the other fuel stagnates in the fuel supply lines. This means that when that fuel is selected again, it may have turned to gel or it may simply not be introduced into the engine at an optimal temperature for combustion. Because the fuel delivery system isn't temperature-conditioned in current systems, the use of certain types of fuel such as higher viscosity fuels, can result in excessive engine system wear, shorter engine life and reduced fuel efficiency.
The present invention pertains to temperature-conditioned fuel delivery in engine systems, such as diesel fuel combustion engines. More specifically, embodiments of the present invention have been designed for use with alternative, higher viscosity fuel types. One skilled in the art will appreciate and recognize that certain components are unique to the present invention and that derivative embodiments can be applicable to various types of engine systems and fuel types.